Start your day by exploring the Cologne Green Belt, a 30 km stretch of parkland around the city. Among the trees, streams, and ponds, you can find a variety of flora and fauna. Make sure to visit the Flora Botanical Garden, where you can see rare plants from around the world. Afterward, hike to the Gremberg Forest, which offers fantastic views of the city and has over 50 km of trails for hiking and cycling.
Experience the beauty of the Wadden Sea National Park. The park covers over 11,000 square kilometers along the North Sea coast and is home to a wide variety of sea creatures and birds. Take a guided tour by boat to see the seals and other wildlife up close. Make sure to visit the Multimar Wattforum museum, which showcases the park's natural history and has interactive exhibits for all ages.
Take a day trip to the Lüneburg Heath Nature Reserve, where you can immerse yourself in one of the largest heathlands in Europe. The reserve is home to a wide variety of flora and fauna, such as deer, wild boars, and birds. Enjoy a scenic hike on one of the many trails in the area. Make sure to visit the Museum Village of Wilsede, where you can learn about the local culture and history of the heath dwellers in the 19th century.
If you have more time, consider visiting other nature reserves nearby, such as the Eifel National Park or Lake Steinhude. Alternatively, if you have less time, skip the boat tour in Wadden Sea National Park and spend more time exploring the nearby islands.